When he was young, Santoso joined the Tangkas Jakarta badminton club before joining the Indonesian National team. In 2005, he won the Vietnam Satellite and the silver medal at the 2005 Southeast Asian Games. His best results on the world circuit until recently were runner-up finishes at the 2008 Singapore, 2007 Swiss, and 2008 Indonesia Open. He was eliminated at the semi-finals in the Japan Open Super Series and the Chinese Taipei Open. In September 2008, Santoso won the Chinese Taipei Open after defeating Roslin Hashim from Malaysia in the final round by scores of 21–18, 13–21, 21–10.